Fibre Optic Sensing


From the operational principle of DAS to its implementation in the railway sector: Find out how the Frauscher Sensonic System revolutionises real-time tracking with fibre optic sensing! 

FOS Enables a Revolutionary Tracking Solution

The Technological Foundation of Sensonic

More data, less effort. Technologies that are used in today’s railway industry must meet the requirements of rapidly progressing digitalisation. Data-based systems are on the rise and they primarily need one thing: reliable sources. Ideally, the sensors that are being used generate highly significant data about all relevant subject matters. At the same time, component and maintenance requirements should remain as low as possible. 

Solutions based on fibre optic sensing (FOS) are increasingly gaining traction in this field of tension. At Frauscher Sensonic, we’ve been focusing on distributed acoustic sensing (DAS) as part of a FOS-based approach for several years already. Tests and comparative studies have shown that this technology offers an immense potential for the implementation of railway applications. 

Distributed Acoustic Sensing

The Operational Principle of DAS

In simple terms, distributed acoustic sensing (DAS) turns fibre optic cables into virtual microphones. This results in an astounding potential regarding monitoring of railway operations and the railway infrastructure. 

In order to function, DAS-based solutions – and thus our system – require only a single-mode optical fibre. The connected Sensonic unit launches 2,000 laser impulses per second into it. Acoustic sound waves radiating against the cable create minimal structure-borne deviations. This alters the backscatter of the laser pulses that are reflected back towards the source. 

The change is measured as a function of the time that has elapsed since the emission of the laser pulse. That’s how the cable becomes a sensor that can monitor up to 100 kilometres of track. 

A Railway-Specific Tracking Solution

FOS in the Rail Sector

Railway-specific solutions based on fibre optic sensing (FOS) enable total distributed area monitoring of all parameters of wheel-rail interaction. That way, current train locations can be determined in real-time and recurring events can be detected. This allows for trend analyses and forecasts regarding the status of trackside infrastructure components or wheels. 

What’s more: The continual development of DAS technology and the employed algorithms facilitate the identification of events in the track’s immediate vicinity. Among them: rockfall, falling trees or people moving in hazardous areas. This information forms the basis of numerous applications and thus opens up a number of entirely new options for development in the railway industry. 

As a customer, you benefit from … 

… continuous monitoring: 

  • in real time
  • across the entire rail network 
  • without on-board or trackside components 

… a single solution for multiple applications: 

  • train tracking
  • asset condition monitoring 
  • safety & security 
Pioneers with Experience

Sensonic – Always on Track

Frauscher Sensonic has comprehensive know-how in the areas of distributed acoustic sensing (DAS) and data processing. Moreover, company experts have decades-long experience in the railway industry. This combination allows us to develop the first quantitative FOS system, which is specifically created to meet the needs and requirements of the railway industry. 

In terms of development, we focus on both components of the system. On the one hand, that’s the fibre optic sensors themselves. By using, the latest generation of quantitative systems, a quantum leap in the informational value of the generated data was achieved in collaboration with Sintela. 

As a second component, the algorithms we use for the preliminary evaluation of the data are continually improved. In addition, we implement logic and intelligence to take into account railway-specific, technical and physical factors in the development of our system. 

You’d like to go more into depth? In our specialist articles, we highlight the current state of the technology, on-going developments, requirements regarding data processing and the industry potential. 

Together Towards the Future

Collaborating with Sensonic

In close collaboration with international technology partners, we focus on practice-oriented development of our tracking solutions. You’d like to become a part of the future of Sensonic?